CNC Router – Materials and File Preparation

The following guide documents approved router materials and CAM resources for preparing files for fabrication.  Use of the IDeATe CNC Router is restricted to approved users; this guide is not a substitute for training and certification.

Materials

The router is available for cutting a wide variety of low-density materials, including wood, foam, and plastics.  We do not support cutting any variety of metals; although the machine is rigid enough for light duty milling in aluminum, we do not have an appropriate lubrication or cooling setup so metals are disallowed.

Approved Materials: Plastics (acrylic, Delrin, ABS, polycarbonate, polyethylene, polypropylene, etc), lumber (plywood, birch, hardwood, MDF, MDO), foam (EPS, XPS, HDF).

Prohibited Materials: aluminum, steel, Homasote, drywall, fabrics, other metals.

Material Warnings:

  • Painted or Glued Materials must be COMPLETELY dry
  • Warping: Certain Materials include significant warping and/or bowing, and are not suitable for CNC Applications. Common problematic materials typically include CDX Grade Plywood, American/Chinese Birch Plywood, and Medium Density Overlay Plywood

Tooling

The router should always be left with the standard set of tools configured in the tool changer.

CAM: Tool Path Planning

Programming a CNC tool is at best a semi-automated process.  After the user defines a 3D CAD model for the part, our CAM systems enable a user to generate a sequence of operations which cut the stock to the final geometry. The CAM system automates the generation of the detailed tool path as it moves back and forth through the stock, using the model and stock geometry as reference.  But the quality of the result depends on the skill of the programmer in choosing the operations and parameters: choice of tool, clearing strategy, roughing vs finishing, depth of cut, feed rate, spindle speed, climb vs conventional, etc.

IDeATe supports CAM for both SolidWorks and Rhino via software on the cluster MacBook Pros.  For Rhino, we use RhinoCAM from MecSoft.  For SolidWorks, we support VisualCAM from MecSoft or HSMWorks from Autodesk.

Each CAM system requires a tool table and post-processor configuration which are supplied separately from the main software installation, and updated from time to time as the machine is maintained.  The tool table specifies the default set of tools installed in the tool changer, along with reasonable defaults for cutting wood.  The post-processor controls how the machine-specific G-code is generated from the CAM path.  The post-processor is highly customized for our specific router, and the output is not transferable between machines.

The current CAM configuration is kept in a git repository at https://github.com/ideate-hunt/CAM.  There are several kinds of files:

.spm files are RhinoCAM or VisualCAM post-processor configurations. Millimeter and inch output are handled with separate files.

.vkb files contain RhinoCAM or VisualCAM tool tables (“knowledge base” files). Millimeter and inch output are handled with separate files.

.cps files contain HSMWorks post-processor scripts. The same script supports millimeters or inches.

.hsmlib files contain HSMWorks tool tables. The same tables work with either millimeters or inches.